ios - crash in core data xcode 8 -

i facing issue in ios swift xcode 8

after setup core data , before insert junk data in purpose of testing fetch function app run correctly no crash , no data after insert data app crash below message

terminating app due uncaught exception 'nsunknownkeyexception', reason: '[<uitableviewcell 0x7f9b26054c00> setvalue:forundefinedkey:]: class not key value coding-compliant key deatials. 

here code

//  import uikit import coredata         // nsfetchedresultscontrollerdelegate needed start woring    in function datacore       class mainvc: uiviewcontroller , uitableviewdelegate,   uitableviewdatasource,nsfetchedresultscontrollerdelegate{  // definning main view table , segment.  @iboutlet weak var tableview: uitableview! @iboutlet weak var segment: uisegmentedcontrol!  // need difine nsfetchedresultscontroller define remaining 3 functions tableview var controller : nsfetchedresultscontroller<item>!  override func viewdidload() {     super.viewdidload()      generatetesedata()     attemptfetch()      tableview.datasource = self     tableview.delegate = self }   // need define 3 main fucntions table view  func numberofsections(in tableview: uitableview) -> int {      if let sections = controller.sections{         return sections.count     }     return 0 }  func tableview(_ tableview: uitableview, numberofrowsinsection section: int) -> int {      // need difine number of rows in section nsfetchedresultscontroller     if let sections = controller.sections{         let sectioninfo = sections[section]         return sectioninfo.numberofobjects     }     return 0 }  func tableview(_ tableview: uitableview, cellforrowat indexpath: indexpath) -> uitableviewcell {      // linking cell var class of itemcell been created in view folder     let cell = tableview.dequeuereusablecell(withidentifier: "cellitem", for: indexpath) as! itemcell      // function been created below:     configurecell(cell: cell, indexpath: indexpath nsindexpath)     return cell }   func tableview(_ tableview: uitableview, heightforrowat indexpath: indexpath) -> cgfloat {     return 150 }  func configurecell (cell:itemcell, indexpath: nsindexpath){     let item = controller.object(at: indexpath indexpath)     cell.configurecellsincellclass(item: item)  }   func attemptfetch () {     let fetchrequest:nsfetchrequest<item> = item.fetchrequest()     let datesort = nssortdescriptor(key: "created", ascending: false)     fetchrequest.sortdescriptors = [datesort]      let controller = nsfetchedresultscontroller(fetchrequest: fetchrequest, managedobjectcontext: context, sectionnamekeypath: nil, cachename: nil)      self.controller = controller      do{        try controller.performfetch()      }catch{         let error = error nserror         print("\(error)")     }  }  // these 2 function update in tableview func controllerwillchangecontent(_ controller: nsfetchedresultscontroller<nsfetchrequestresult>) {     tableview.beginupdates() } func controllerdidchangecontent(_ controller: nsfetchedresultscontroller<nsfetchrequestresult>) {     tableview.endupdates() }  //this function preforme functions <data core> func controller(_ controller: nsfetchedresultscontroller<nsfetchrequestresult>, didchange anobject: any, @ indexpath: indexpath?, type: nsfetchedresultschangetype, newindexpath: indexpath?) {      switch(type)     {     case.insert:         if let indexpath = newindexpath {             tableview.insertrows(at: [indexpath], with: .fade)         }         break      case.delete:         if let indexpath = indexpath{             tableview.deleterows(at: [indexpath], with: .fade)         }         break      case.update:         if let indexpath = indexpath {             let cell = tableview.cellforrow(at: indexpath) as! itemcell             configurecell(cell: cell, indexpath: indexpath! nsindexpath)         }         break     case.move:         if let indexpath = indexpath {             tableview.deleterows(at: [indexpath], with: .fade)          }         if let indexpath = indexpath {             tableview.insertrows(at: [indexpath], with: .fade)         }         break } } 

at point system cun without crash after add insert function in below it's start crashing

func generatetesedata(){     let item = item(context: context)      item.title = "imac"     item.price = 2000     item.details = "soon" } 

this view cell file

class itemcell: uitableviewcell {   // view take label view , link here   @iboutlet weak var thump: uiimageview! @iboutlet weak var title: uilabel! @iboutlet weak var price: uilabel! @iboutlet weak var deatials: uilabel!   // using function set values of items labels been linked before in upper section  func configurecellsincellclass (item:item){     title.text = item.title     price.text = ("$\(item.price)")     deatials.text = item.details } } 

thank guys in advance

as @larme says problem related iboutlet not reflect in class anymore.

disconnect bad outlet